Method of and means for operating on sheet metal articles



Dec M, 19356 c. F. MERRILL 1-:r AL 220249108 METHOD OF AND MEANS FOROPERATING ON SHEET METAL ARTICLES Filed Sept; 6, 1933 2 Sheets-Sheet l am w L m N Em. /\O Wi W Z EC J ET mu wc 1935- c. F. MERRILL ET AL2,024,108

'METHOD OF AND MEANS FOR OPERATING ON SHEET METAL ARTICLES Filed Sept.6, 1933 2 Sheets-Sheet 2 Z 32 INVENTORS. W/ 71 555. CHA/E'LES F. MERE/LLC2 /N7' /Y\5. CoBlJE/Y. 650565 (I You/vs ATTTDRNEY.

Patented Dec. 10, 1935 UNIT ED STATES.

IWETHOD OF AND MEANS FOR OPERATING ON SHEET METAL ARTICLES Charles F.Merrill and George C. Young, Hopedale, Mass, assignors to DraperCorporation, Hopedale, Mass, a corporation of Maine ApplicationSeptember 6, 1933, Serial No. 688,362

17. Claims.

The present invention pertains to the making of sheet metal articlessuch as drop wires and to the removal of burrs from apertures therein.We will disclose, as a specific example of the utility of our invention,adaptation of the sameto the making of drop wires only, but it should beunderstood that such=disclosure is intended to be illustrative ratherthan for purposes of limitation, the true scope of the invention beingdefined in the appended claims.

A drop wire of the type herein disclosed is a flat sheet metal articleusually provided with a detector-bar slot and a thread aperture. Thesedrop wires are utilized in warp stop motions of looms by being'suspendedfrom the warp threads, which threads pass through the thread aperturesmentioned. It is of utmost importance that the drop wires, andparticularly the apertures therein, present no sharp or rough edgeswhich would be likely to chafe or break the threads. Commercial methodsof forming apertures in sheet metal articles usually leave burrs on theedges of the apertures, and it is with the removal of such burrs thatour invention is primarily concemed.

An object of the invention is to provide a novel burr-removing machine,in the form of a flying burr-removing tool such as a milling cutteroperating on a continuously fed strip of' partially formed sheet metalarticles.

A further object of the invention is to provide a novel and improvedmethod of making apertured sheet metal articles and removing the burrsfrom the apertures therein.

Other objects will, in part, be herein-after more specificallyenumerated and will, in part, become obvious as the descriptionproceeds.

In attainment of the foregoing and other objects we have devised amethod which embraces the steps of punching out a strip of sheet metalto form a series of connected, partially formed drop wires, thereafterfeeding the strip continuously while removing the burrs therefrom, andsubsequently severing the strip at intervals into individual drop wires.

For more detailed disclosure of the preferred embodiment of ourinvention, reference may be had to the accompanying drawings, of which:

Fig. 1 is a side elevation, partially diagrammatic and with parts brokenaway, of the form of machine which we prefer;

Fig. 2 is a detail of the preferred form of burrremoving tool;

Fig. 3 is a sectional elevation taken approximately on line 3-3 of Fig.1, except that one of the spindles has been sectioned;

Fig. 4 is a fragmentary plan view of the work ing in section; and

Fig. 5 is a detail, in section, taken approximately on line 5-5 of Fig.1.

In making drop wires in accordance with the present invention, acontinuous strip of sheet metal of the same width as a finished dropwire 5 is utilized. The strip is continuous only in the sense that it isof indefinite length. The strip is then punched out to form a series ofpartially-formed drop wires W connected by narrow connecting portions C.The particular drop 10 wires illustrated are provided with circularthread apertures T and elongated apertures for slots S for reception ofa detector bar (not shown). This is but one of the various forms of dropwires which may be made. 15

The apertures T and S, which are spaced apart longitudinally of thestrip, must have the burrs removed therefrom before the drop wires canbe put into use. In removing these burrs the strip of partially formeddrop wires is fed by go means of a pair of continuously rotated drums Iand 2. The portion W of the strip, Fig. 1, may come directly from apunch press, not shown, or from any other suitable source of supply.This: strip passes over the drum l and. proceeds as at W 25 past a burrremoving tool 3 to drum 2. The strip then passes about the drum 2 andthen in the opposite direction (toward the left in Fig. 1) todrum I.During this latter passage of the strip it is twisted about its ownlongitudinal axis by 39 pins 3, 5-, to present its opposite face to thedrum I. After passing about the drum I by the side of the first run ofthe strip, the strip is fed parallel to the portion W past anotherburrremoving tool 6, as at W and thence to a pair 35 of continuouslyrotating feed rolls 1, I.

The tools 3 and B are, in the present embodiment, milling cutters of aspecial shape, although other burr-removing tools may be employed. Thesecutters are constructed and 40 mounted to operate on the strip while thelatter is being continuously fed. The machine will be hereinafter morefully described.

The final step in the method, insofar as the same is of our invention,is cutting out the con- 5 necting portions C-in other words, severingthe strip at regular intervalsto form individual drop Wires. Thesevering may be done by any suitable means, there being diagrammaticallyillustrated on Fig. 1 a conventional die 8 and double edged 5 shearblade 9 operated from a crank It by means of a pitman II.

It is noted that the shear operates on they strip while the same isbeing continuously fed, and such is the preferred mode of operation.How- 55 ever, the strip or the drop wires may be subjected to otheroperations either before or after any of the steps of the method hereindisclosed.

In the preferred embodiment of machine for performing theburr-removingsteps of the meth- 0 0d, the mechanism is carried by atable l2 which.

may be mounted on legs l3, l3. Stands l4, [4 on the table support thefeed drums l and 2 which are rotated continuously by any suitable means,not shown. Upright posts I5, 15 on the table support a fiat bed IS onwhich are mounted a work supporting block I! and standards [8, I8. Thestandards l8 are integrally joined by a hori- .zontal cross bar !9 whichreceives a shaft 20 which is fixed therein as by set screws 2|, 2| (Fig.3).

It will be noted that'four spindles are supported on the shaft 28. Thespindles carrying tools 3 and 6 operate, respectively on the portions Wand W of the same strip. The spindles carrying tools 3' and 6 areduplicates of the other two but operate on a different strip. Theduplication of parts to operate on, a plurality of strips simultaneouslymay be extended, to provide for still more strips, or the machine may beconstructed to operate on only one strip.

Eccentric members 22 are loosely mounted on the shaft 20, one for eachspindle. Like reference numerals are applied to all the spindles as.

they are of duplicate construction, and the description immediatelyfollowing may be applied to any one of thespindles.

A frame 23 is bored to loosely receive the eccentric 22 but eccentricand frame are constrained to pivot together about the shaft 23 by meansof a spring 24 engaging the notched periphery of a wheel 25 formedintegrally with the eccentric. The construction is such that theeccentric may be manually rotated relative to the frame to therebyadjust the latter vertically. The frame 23 is provided with verticallyspaced bearings 26, 21 in which the spindle 28 is slidably and rotatablymounted. A cap 29, fixed to bearing 26, is recessed to receive a coilspring 38 which bears at its lower end against a thrust bearing 3| forthe spindle and its upper end against an adjusting screw 32 in the cap.By this means the spindle is yieldably urged axially toward the stripbut is capable of a limited axial movement.

The vertical, or axial, movement of the spindle is limited by engagementof the driving pulley 33 with the bearing 26 or 2'1, the pulley beingfixed to the spindle Pivotal movement of the frame 23 and spindle aboutthe shaft 20 is limited by means of cross bars 34 extending entirelyacross the machine and carried by adjusting screws 35, 35 in thestandards l8. The frame 23, beyond bearing 21 extends downwardly as at36 and carries a horizontal cross member 31 which is engaged by the bars34 to limit the aforesaid pivotal movement. A spring 38 may beinterposed between the rear bar 34 and the cross member 35 to assistgravity in yieldingly urging the frame clockwise, Fig. 1, to therebyurge the tool laterally in a direction opposite to the direction ofmovement of the strip therebeneath.

A conventional collar or socket 39 is provided on the spindle forreceiving the tool. The tool may also be guided by a bushing 40 carriedby the cross member 3?. The spindle and tool may be rotated by anysuitable means such as a system of belts and pulleys indicated generallyat 4] and associated with the pulley 33.

It will be apparent that, by means of the fore going mechanism, the toolwill be given a so-called flying movement. That is, the tool will haverepeated cycles of bodily movements comprised of a movement axially intoan aperture in the work, then laterally with the work while operatingthereon, then axially out of the aperture and,

finally, laterally in a direction opposite to the direction of movementof the work, to the point of beginning, where it rests until the nextsucceeding aperture is presented to the tool. While various forms oftools may be used for the burr- 5 removing operation, there is shown indetail in Fig. 2 a milling cutter which it is preferred to use.

The milling cutter 3, Fig. 2, is of the so-called end mill type butmodified from usual practice in 10 that the tip 42 is smooth, slightlyrounded, and devoid of any cutting edges. The end of the cutter, asdefined by the cutting portions 43, is frusto-conical and merges withvery short, axially extending cutting edges 44. The diame- 15 ter of thecutter, at edges 44, is slightly less than the diameter of the threadapertures T and the vertical extent of these edges should be about equalto or less than the thickness of the sheet metal strip. Obviously, theshape of the cutting 20 edges 43, 44 may be varied to provide any typeor shape of finished surface surrounding the apertures which may bedesired. Furthermore, the invention in its broader aspects embraces theuse of other burr-removing tools, such as tools 25 having an abrasiverather than a cutting action. However, any such tool which isspring-pressed toward the work and rides along the Work betweenapertures should be provided with a smooth tip, such as 42', to avoidmutilating the surfaces beso tween the apertures.

The rotating tool 3 is held substantially normal to the plane of thestrip therebeneath and departs from a truly normal position only byreason of the fact that the present frame 23 has a pivotal rather than asliding movement. It is contemplated that this as well as other of theparticular means herein disclosed may be modified or changed within thescope of the appended claims without departing from the spirit of the 40invention.

We claim as our invention:

1. In a method of removing burrs from punched apertures in sheet metalarticles, the steps of continuously feeding a strip of sheet metal whichcontains spaced apertures for a plurality of such articles, removing theburrs from said apertures by rotating a tool and moving the same withthe strip while operating in said apertures, and thereafter severingsaid strip at regu- 50 lar intervals into a plurality of said articles.

2. In a method of removing burrs from punched apertures in sheet metalarticles, the steps of continuously feeding a strip of sheet metal whichcontains spaced apertures for a plu- 55 rality of such articles,removing the burrs from ,one face of said strip by rotating a tool inand strip lengthwise and, while the strip is being so fed, imparting toa rotating burr removing tool a cycle of movements for each aperture,which no cycle includes movements of the tool first, into operativeengagement with a given aperture, then with the moving aperture whileremoving the burrs therefrom, then out of engagement with said apertureand, finally, opposite to the direc- 7 tion of movement of said strip tothe point of beginning.

4. In a method of making and removing burrs from drop wires, the stepsof continuously feeding a strip of sheet metal which containslongitudinally spaced apertures for a multiplicity of drop wires,removing the burrs from said apertures by rotating a tool therein whilethe strip is being fed continuously as aforesaid, and thereaftersevering said strip at regular intervals to form a multiplicity of dropwires.

5. In a method of making drop wires, the steps of first punchinglongitudinally spaced apertures in a continuous strip of sheet metalwithout completely severing said strip, then continuously feeding thepunched strip while removing the burrs from the apertures therein with arotating tool, and thereafter severing said strip at regular intervalsto form a multiplicity of drop wires.

6. In a method of making and removing burrs from drop wires, the stepsof continuously feeding a strip of sheet metal which contains spacedapertures for a multiplicity of drop wires, removing the burrs from saidapertures by simultaneously rotating a tool and moving the same with thecontinuously moving strip while operating on said apertures, andthereafter severing said strip at regular intervals to form amultiplicity of drop wires therefrom.

'7. In a method of making drop wires, the steps of taking a strip ofsheet metal of the same width as a finished drop wire, simultaneouslypunching apertures and notches in said strip at intervals correspondingto the length of the finished drop wires, and thereafter continuouslyfeeding the apertured and notched strip while performing thereon theoperations of removing the burrs from the apertures therein and severingthe strip at each notch, to thereby form a multiplicity of drop wires.

8. In a method of making and removing burrs from drop wires, the stepsof continuously feeding a strip of sheet metal which contains spacedapertures for a multiplicity of drop wires, removing the burrs from saidapertures by simultaneously rotating a tool and moving the samealternately with the continuously moving strip while operating on anaperture and in the opposite direction to engage the next aperture, andthereafter severing said strip at regular intervals to form amultiplicity of drop wires.

9. In a method of making and removing burrs from drop wires, the stepsof continuously feeding a strip of sheet metal which contains spacedapertures for a multiplicity of drop wires, removing the burrs from saidapertures with a rotating end mill by moving such mill alternately withthe continuously moving strip in engagement with an aperture and in theopposite direction to engage the next succeeding aperture, andthereafter severing said strip at regular intervals to form amultiplicity of drop wires.

10. A machine for removing burrs from apertures in a strip of sheetmetal, comprising in combination, means for continuously feeding saidstrip, a flying end mill entering into and operating on said apertureswhile the strip is being so fed, and means for operating said end millas aforesaid.

11. A machine for removing burrs from apertures in a strip of sheetmetal, comprising in combination, means for continuously feeding saidstrip lengthwise, a flying burr removing tool entering into andoperating on said apertures while the strip is being so fed, and meansfor operating said tool as aforesaid.

12. A machine for removing burrs from longitudinally spaced apertures ina strip of sheet metal, comprising in combination, means forcontinuously feeding said strip lengthwise, a flying end mill enteringinto and removing the burrs from said apertures successively while thestrip is being so fed, and meansfor operating said end mill asaforesaid.

13. A machine for removing burrs from apertures in a strip of sheetmetal, comprising in combination, means for continuously feeding saidstrip, a rotating burr removing tool positioned approximately normal tothe continuously fed strip, supporting and guiding means for said toolpermitting the latter to move both normal to and longitudinally of thesaid strip, means for yieldingly urging said tool toward the strip andmeans for yieldingly urging said tool in a direction opposite to thedirection of movement of the strip.

14. A machine for removing burrs from apertures in a strip of sheetmetal, comprising in combination, means for continuously feeding saidstrip, an end milling cutter having a rounded non-cutting tip whichcutter is positioned approximately normal to the continuously fed strip,supporting and guiding means for said cutter permitting the latter tomove both normal to and longitudinally of the said strip, means foryieldingly urging said cutter toward the strip and means for yieldinglyurging said cutter in a direction opposite to the direction of movementof the strip.

15. A machine for removing burrs from apertures in a strip of sheetmetal, comprising in combination, means for continuously feeding saidstrip, a rotating burr removing tool having a smooth non-cutting tipwhich tool is positioned approximately normal to the continuously fedstrip, supporting and guiding means for said tool permitting the latterto move both normal to and longitudinally of the said strip, means foryieldingly urging said tool toward the strip and means for yieldinglyurging said tool in a direction opposite to the direction of movement ofthe strip.

16. A machine for removing burrs from longitudinally spaced apertures ina strip of sheet metal, comprising in combination, means forcontinuously feeding said strip lengthwise, a rotating burr removingtool having a smooth, noncutting tip, a movable carriage supporting saidtool for movement longitudinally of said strip,

said tool being slidably supported by said carriage for movement normalto said strip, means for yieldingly urging said carriage and tool in adirection opposite to the direction of movement of said strip and meansfor yieldingly urging said tool toward said strip.

17. A machine for removing burrs from longitudinally spaced apertures ina strip of sheet metal of indefinite length, comprising in combination,spaced work supporting elements about which said strip is wrapped toprovide two parallel runs of the strip, means for feeding said stripcontinuously, and a flying burr removing tool for each of said runs,said tools entering into and removing the burrs from opposite sides ofsaid apertures while the strip is being fed continuously as aforesaid.

CHARLES F. MERRILL. GEORGE C. YOUNG.

